chore(link checker): Move to Lychee for link checking

.github/workflows/lint.yml

@@ -3,7 +3,7 @@ name: Lint
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
     types:
       - opened
@@ -13,6 +13,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
-      - run: npx --package markdownlint-cli markdownlint **/*.md --ignore node_modules
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
+      - run: npm ci
+      - run: npm run lint

.github/workflows/offline-link-check.yml

@@ -0,0 +1,18 @@
+name: Offline link check
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  link_check:
+    runs-on: ubuntu-latest
+    steps:
+      uses: actions/checkout@v5
+      uses: lycheeverse/lychee-action@v2
+        # Only check local files, no network requests
+        args: --offline --no-progress 'src/content/docs/**/*.md'
+        # Fail job when lychee returns a non-zero exit code
+        fail: true

CONTRIBUTING.md

@@ -4,8 +4,8 @@ We welcome contributions of all kinds to AllContributors.
 
 ## 13 August 2025 Update:
 
-Currently, we are doing some work to revive the project. The documentation 
-website is not online but we are working to get it online soon. 
+Currently, we are doing some work to revive the project. The documentation
+website is not online but we are working to get it online soon.
 
 ************* THE LINKS BELOW DON'T CURRENTLY WORK ******
 

lychee.toml

@@ -0,0 +1,52 @@
+#############################  Display  #############################
+
+# Verbose program output
+# Accepts log level: "error", "warn", "info", "debug", "trace"
+verbose = "info"
+
+# Don't show interactive progress bar while checking links.
+no_progress = false
+
+#############################  Cache  ###############################
+
+# Enable link caching. This can be helpful to avoid checking the same links on
+# multiple runs.
+cache = true
+
+# Discard all cached requests older than this duration.
+max_cache_age = "2d"
+
+#############################  Runtime  #############################
+
+# Number of threads to utilize.
+# Defaults to number of cores available to the system if omitted.
+threads = 2
+
+# Maximum number of allowed redirects.
+max_redirects = 10
+
+# Maximum number of allowed retries before a link is declared dead.
+max_retries = 2
+
+# Maximum number of concurrent link checks.
+max_concurrency = 14
+
+#############################  Requests  ############################
+
+# When links are available using HTTPS, treat HTTP links as errors.
+require_https = true
+
+# Fallback extensions to apply when a URL does not specify one.
+# This is common in documentation tools that cross-reference files without extensions.
+fallback_extensions = ["md", "mdx", "html"]
+
+#############################  Exclusions  ##########################
+
+# Exclude URLs and mail addresses from checking. The values are treated as regular expressions
+exclude = []
+
+# Check fragments - internal links in pages
+include_fragments = true
+
+# Check email addresses
+include_mail = true